A pressure vessel for containing fluid under pressure may include a tank and a plug with a rupturable closure wall. In such a pressure vessel, the plug is fixed and sealed to an outlet portion of the tank to close the tank. The plug supports the closure wall in a position in which the closure wall blocks the fluid from flowing outward from the tank. Additionally, the plug may be constructed as an outlet manifold with a fluid flow conduit extending from the closure wall to a plurality of outlet openings.
The closure wall is ruptured when the fluid is to be released from the pressure vessel. As known in the art, the closure wall may be ruptured by fluid pressure forces acting outward against the closure wall, or by the impact of a piston or the like. The fluid then flows outward from the tank past the ruptured closure wall and into the plug, and further outward through the conduit and the outlet openings in the plug. In some cases, a predefined breakaway part becomes severed from the closure wall when the closure wall is ruptured. The breakaway part may be carried outward into the conduit by the fluid flowing outward from the tank.